Prostate cancer is the most common form of cancer in men. More than 240,000 men in the U.S. are diagnosed with prostate cancer each year. One method of treating prostate cancer is brachytherapy, also referred to as “radioactive seed implantation.” During this procedure, radioactive seeds are placed into a prostate through the use of needles. It is important to place the radioactive seeds in the correct locations. As such, the use of a simulator may facilitate the development of hand-eye coordination that is crucial to the brachytherapy procedure. A simulator may also provide a means for measuring performance and competency in a prostate brachytherapy surgical technique. In particular, a simulator may be used to train a user and/or a machine operated by a user that performs a prostate brachytherapy procedure.
The prostate brachytherapy procedure consists of implanting many small radioactive “seeds” directly into the prostrate via needles inserted through the perineum. The procedure is typically done under local anesthesia and involves using a transrectal ultrasound (TRUS) probe to visualize the entire procedure in real time. After the patient is prepped and on the operating table with the TRUS probe in place, the physician inserts about 15-25 needles through the perineum. Each needle may be placed by hand while under continuous visualization by the TRUS to confirm the exact location of needle placement. Alternatively, each needle may be placed by a machine designed to perform the prostate brachytherapy procedure.
The brachytherapy needles may be evenly spaced throughout the entire prostate gland. Additionally, care is taken to avoid inserting needles into the urethra and/or the rectal wall. After the needles are in place, the physician uses an applicator device to insert the radioactive seeds. In particular, the physician may use a ramrod to slide the radioactive seeds down the bore of the needle until each seed exits the needle and embeds itself into a desired location within the prostate. After the first seed is placed, the needle may be withdrawn about one centimeter and another seed is deployed through the needle; this is repeated until the entire length of the prostate has been “seeded,” after which the physician removes the needle. The physician then moves on to the next needle, implants more seeds in a line across the prostate in a manner described above, and repeats the seed implantation process for all of the remaining seeds. In this process, a total of 50-100 seeds may be implanted.
After all of the seeds are implanted, routine x-ray fluoroscopy or cystoscopy imaging studies are performed to verify the correct placement of the seeds and to rule out any accidental seed placement in the bladder. If a seed is seen in the bladder, it can be removed by a urologist using fiberoptic cystoscopy. The entire brachytherapy procedure can be completed in about 90 minutes, and the patient is discharged home after the anesthetic wears off. Most of the seeds' radioactivity is given off over the course of a few months, during which time the prostate cancer cells are sterilized by the radiation. Although the seeds become essentially inert after a few months, the seeds remain in the patient permanently.
It has long been established that higher doses of radiation delivered to the prostate results in higher rates of cure, but the amount of radiation that can be safely delivered is constrained by the method used to deliver the radiation. The biggest advantage of prostate brachytherapy is its ability to deliver extremely high doses of radiation within a small volume encompassing the prostate. Prostate brachytherapy does have some limitations, however. Specifically, as a minor surgical procedure, it is heavily operator dependent. It involves potentially hazardous materials, and, in the hands of an inexperienced practitioner, it can be quite dangerous and lead to significant iatrogenic (i.e., physician-caused) problems. As such, it is beneficial to develop efficient training processes to increase the skills of physicians to perform this procedure.